Covid: why some countries have reduced isolation (and the doubts it generates among some scientists)

As the omicron variant advances, some countries have relaxed isolation standards.

On previous occasions of the coronavirus pandemic, before the appearance of a new variant, the authorities have strengthened restrictive measures to avoid contagion.

Now, however, countries such as the United States, United Kingdom, Spain and Argentina have decreased the number of days that a person infected with Covid-19 must remain isolated after overcoming the disease or being asymptomatic.

In the US, the person will no longer have to isolate himself for ten days, but only for five. In the United Kingdom, Spain and Argentina, they will spend ten days in quarantine to only seven, with specific indications in each country.

The authorities of those nations have said that reducing isolation is a way of maintaining a certain degree of normalcy in the daily life of its citizens.

“If you are asymptomatic and infected, we want people to go back to work,” Dr. Anthony Fauci, the White House’s chief medical adviser, said in an interview with CNN on Wednesday.

Some independent specialists, however, have shown their reservations regarding these measures, especially when more data is still lacking to know the behavior of omicron.

U.S

So far, the US is the country that has announced the largest quarantine cut.

On Monday, the US Centers for Disease Control and Prevention (CDC) released its new guide.

“People with covid-19 should be isolated for five days and if they are asymptomatic or if their symptoms are improving (no fever for 24 hours), continue with 5 days of wearing a mask when they are around other people, to minimize the risk of infect people they come across, “the CDC says on its website.

The measure comes at a time when the US records contagion records since the beginning of the pandemic.

On December 27, the CDC reported 441,278 cases, by far the highest number of daily cases the country has ever reported.

According to Fauci, cutting isolation is a way to avoid that “many people are left out (of their activities)” given the large number of cases they are having and still hope to have by omicron.

The CDC indicates that this change is motivated by science, which has shown that the greatest transmission of SARS-CoV-2 occurs in the early stages of contagion, usually between 1 and 2 days before the development of symptoms, and 2 or 3 days after the development of symptoms.

critics

The CDC announcement and Fauci’s explanations have drawn criticism.

One of them is that of Eric Topol, professor of Molecular Medicine and vice president of the Scripps Research bioscience research institute in California.

In an article titled “A Very Bad Day at the CDC,” posted on his blog Dec. 28, Topol lists five reasons why he considers the measure “hollow.”

First, it recognizes that while further disruption to the workforce and ordinary people must be avoided, “There is no data or evidence to support the measure”.

Second, it criticizes that the CDC does not indicate that the isolated person should have an antigen test or PCR that shows that he is no longer positive and that therefore he can circulate.

Third, it mentions that there is not enough data about how long the spread lasts and the elimination time of the virus in its omicron variant, something that is known for the delta variant, for example.

Fourth, the expert points out that the CDC guide “does not mention a single word” about the vaccination status of the infected person.

“We know from previous studies that there is a faster elimination (of the virus) among those vaccinated than among people who were not vaccinated, but the CDC recommendation does not account for this, “writes Topol.

And finally, he notes that the CDC guidance “assumes that all people handle the virus in a similar way when, in fact, there is considerable variability.”

England

In the other countries, the cut has been less drastic.

In England, for example, infected people had to isolate themselves for ten days, but since December 22 they can be isolated for only seven days if they present a negative test on days six and seven.

The measure applies the same to all people, regardless of their vaccination status.

In the UK, the omicron variant has created staff shortages in businesses, on trains and in health services.

Richard Tedder, a member of the UK Clinical Virology Network, said this measure is based on the assumption that a person with two negative tests is unlikely to transmit the virus.

“On a balance of probabilities this is probably correct,” Tedder told the Science Media Center website.

Tedder, however, cautions that he has two reservations.

The first has to do with the fact that in England people can do tests themselves which may be less sensitive than a PCR.

And your other caveat is that the decrease in isolation time should apply only to those people who do not have any preconditions or who are under a therapy that affects their immune system, since in these cases the virus can act differently.

Spain

In Spain, the Public Health Commission approved that as of this Thursday, people who test positive for covid but who do not have symptoms will be able to reduce their quarantine from ten to seven days.

To leave the isolation, an antigen test or PCR will not be necessary.

“It seems reasonable to me,” says Dr. Salvador Peiró, a doctor specializing in Public Health and a researcher in Pharmacoepidemiology at FISABIO, a biomedical research foundation dependent on the Generalitat Valenciana, in Spain.

“The contagion capacity is reduced from the sixth or seventh day. Surely some escape, but it is also true that they escape us everywhere,” says the expert.

“The social disruption that omicron can create is enormous, we are talking about trains, airplanes, police, firefighters, health “.

For the expert, reducing the isolation allows to focus attention on the cases that are more serious.

Peiró, however, cautions that the measure has several operational challenges in practice.

“There is the challenge of defining exactly what is asymptomatic,” says the expert. “What if what I have is a slight headache?” He wonders.

In that sense, he says that the key is for doctors and patients to have clear parameters on how to act.

Furthermore, it points out that someone who is asymptomatic today may not be asymptomatic tomorrow.

This Thursday, Spain registered 161,688 new infections, its highest number since the pandemic began, after more than a week with record numbers of daily infections.

As for the US, Peiró maintains that he does not agree with Topol’s position.

“I disagree a lot,” he says.

“I understand the part where it says we don’t have enough evidence, but my question is what are the alternatives for each measure.”

“The alternative is millions of days of isolation for many people who probably don’t need it.”

“It does not seem crazy to me that the US has decided five days, (but) the British and the Spanish seem much more prudent with seven,” he concludes.

Argentina

On Wednesday, Argentina approved reducing quarantines for close contacts and vaccinated infected.

On Thursday, the country surpassed 50,000 daily cases of coronavirus for the first time.

With the new measure, asymptomatic close contacts who have the complete vaccination scheme will have to be isolated for only five days and not ten, as it was before.

Confirmed cases with a complete scheme should no longer be isolated for 10 days, but only for seven.

“It makes sense, especially at a time when there are many cases and many people isolated by close contact,” the doctor tells BBC Mundo. Martin Hojman, infectious disease doctor member of the Argentine Society of Infectology.

“You have to do it with the utmost care, that is, do the necessary activities but do not relax the measures completely, continue with the care, use the mask, avoid social gatherings, avoid closed places without ventilation.”

Hojman explains that omicron is much more contagious than other variants, but that this is not translating into more hospitalizations or deaths.

“As long as hospitalizations and mortality remain within an expected number and the health system is not in danger of collapsing, it seems to me that the restrictive measures do not have much application,” says the doctor.

“If bed occupancy and mortality begin to change, activity restriction measures will be necessary.”

And when comparing Argentina’s measures with those of the US, Hojman considers Argentina’s regulation “to be more prudent.”

“It seems to me that in the US they took into account the economic issue more than the health issue, because there with the positives, especially in the unvaccinated, a greater risk is being run,” concludes the specialist.

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